Tazarotene has the chemical name: ethyl 6-[2-(4,4-dimethylthiochroman-6-yl)-ethynyl nicotinate. Tazarotene is a retinoid prodrug which is converted to its active form, tazarotenic acid, by rapid de-esterification in most biological systems. Tazarotenic acid binds to all three members of the retinoic acid receptor (RAR) family; RARα, RARβ, and RARγ, but has relative selectivity for RARβ and RARγ, and may modify gene expression.
Allergan, Inc. market TAZORAC® (tazarotene) cream and TAZORAC® (tazarotene) gel for the treatment of acne and psoriasis.
The treatment of skin disorders using a retinoid or an antibiotic in combination with benzoyl peroxide is of great interest to dermatologists. However, this presents challenges to the formulation chemist insofar as retinoids and antibiotics often readily degrade in the presence of benzoyl peroxide. Accordingly, the active ingredients are often not mixed together until immediately before administration to the patient, or are administered at different times of the day. Alternatively, the retinoid or antibiotic might be protected (e.g. by encapsulation) from reaction with the benzoyl peroxide, or the active ingredients may be housed in separate chambers of a dual chamber dispenser.
Thus, there is a need for improved dermatological compositions containing a combination of active ingredients which provide the requisite convenience, efficacy and shelf life. Specifically, a need exists for the identification of stable retinoids that may be combined with benzoyl peroxide in a pharmaceutical composition.